论文部分内容阅读
为了深入了解冲击冷却在涡轮叶片前缘的应用效果,建立了其附近梯形内冷通道的放大模型,对冲击冷却进行试验研究,测量腔内流场和壁面换热特性,在已掌握流动结构的基础上进行换热分析,更好地理解此类受限通道内冲击冷却的强化换热机理,为更高效的内冷通道设计提供参考。使用热电偶对通道靶面温度进行了详细测量,研究射流角度、横流和射流雷诺数对靶面换热努塞尔数的影响规律。结果表明:较低位置射流对靶面具有较强的冲击作用,而较高位置射流未对靶面形成冲击;射流入射角度的增加会提高较低位置射流在靶面上的冲击换热能力,对较高位置射流的换热没有明显影响;较强的横流将严重削弱靶面冲击区的换热能力,射流雷诺数的增加将大幅提高整个靶面上的换热能力;换热试验结果与前期研究的流场分析结论非常一致。
In order to understand the effect of impingement cooling on the leading edge of turbine blade, an enlarged model of the trapezoidal internal cooling passage is established to study the impact cooling and to measure the flow field and wall heat transfer characteristics in the cavity. Based on the heat transfer analysis to better understand the impact of such limited channels cooling enhanced heat transfer mechanism for the more efficient design of the internal cooling channel to provide a reference. The thermocouple was used to measure the target surface temperature in detail. The effects of jet angle, cross flow and jet Reynolds number on the Nusselt number of target surface heat exchange were studied. The results show that the jet at the lower position has a strong impact on the target surface, while the jet at the higher position has no impact on the target surface. Increasing the incident angle of the jet can improve the impact heat transfer capability of the jet at the lower position on the target surface, Which has no obvious effect on the heat transfer of the higher position jet. The strong cross flow will seriously weaken the heat transfer capacity of the impact area of the target surface. The increase of the Reynolds number of jet will greatly increase the heat transfer capacity of the whole surface. The flow field analysis results of previous studies are very consistent.